This invention relates to a bias circuit for a transistor, and more particularly to a bias circuit for a microwave field-effect transistor.
A field-effect transistor (FET) is more difficult to bias than bipolar transistors. This is particularly true of a gallium arsenide (GaAs) microwave FET because the gate-to-source voltage, V.sub.gs, is frequently comparable to and sometimes larger than the drain-to-source voltage, V.sub.ds, whereas most biasing schemes rely upon the latter being much greater than the former.
Biasing of a GaAs FET can be achieved in a conventional manner by selection of resistors, or by potentiometer adjustments, but such conventional biasing has the disadvantage of being temperature sensitive, and often expensive, unreliable, or time consuming to adjust. An object of this invention is to provide a biasing circuit for a FET.